1. Field of the Invention
The present invention relates to a fat-soluble drug composition comprising a fat-soluble component and an emulsifier, specifically a fat-soluble drug composition for capsules.
2. Description of the Related Art
Conventionally, use of soft capsules comprising a fat-soluble component raised problems of low absorption rate in the living body, e.g., in the stomach, intestine, etc., and slow absorption rate. To solve such problems, self-emulsifying type fat and oil compositions comprising a polyglycerol fatty acid ester are known (see Japanese Examined Patent Publication (JP-B) No. 4-74339 and Japanese Patent Application Laid-open (JP-A) No. 61-12632). However, those compositions do not have sufficient self-emulsifying property. Furthermore, they have a problem of high viscosity, which makes handling of them difficult.
Moreover, there are known methods which comprises filling a soft capsule with a self-emulsifying type fat and oil composition containing polyglycerol condensed-ricinoleic acid ester and polyglycerol laurate as emulsifiers (see JP-A No. 2004-115544 and JP-A No. 2004-135681). However, the content percentages of the polyglycerol condensed-ricinoleic acid ester in those compositions are high, i.e., in the range of 15 to 60 wt %, which causes a problem of decreased content of the fat-soluble components in the soft capsule. Furthermore, where the content of the emulsifier in the soft capsule increases, the taste becomes bad when the soft capsule is used as an oral chewable-type capsule, etc., resulting in causing unpleasant feeling.